# NIST SP 800-53 Rev. 5 SC-20 — Secure Name/Address Resolution Service (Authoritative Source) - Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-20-secure-name-address-resolution-service-authoritative-source - Section: [Compliance](https://support.icompaas.com/compliance) › [NIST SP 800-53 Rev. 5 Controls](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5) › SC — System and Communications Protection - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **NIST SP 800-53 Rev. 5**·Control `SC-20`·high·Component: **System and Communications Protection** ## What this control requires > Provide additional data origin authentication and integrity verification artifacts along with the authoritative name resolution data returned in response to external name/address resolution queries. Also, provide means to indicate the security status of child zones and, if the child supports secure resolution services, enable verification of the chain of trust between parent and child domains within a distributed, hierarchical namespace. This control supports the Name/Address Resolution Security Mechanism capability within the System and Communications Protection family. > > — NIST SP 800-53 Rev. 5, Control SC-20 ### In plain English Provide additional data origin authentication and integrity verification artifacts along with the authoritative name resolution data returned in response to external name/address resolution queries. In practice, this means you can prove you access management-level controls on a defined cadence. ## Why it matters SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed. This control is rated **high**. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation. ## What an auditor looks for A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan. Within **System and Communications Protection**, the assessor will trace your implementation back to the catalogue reference (Control SC-20) and look for objective evidence on the latest two assessment cycles. ## How to implement 1. Write a short policy stating intent, scope and named owner. 2. Encode it as a platform guardrail — SCP, Azure Policy initiative, Organisation Policy, or repository policy. 3. Wire a monitoring signal that catches drift (CSPM rule, SIEM rule, scheduled query, Workspace alert) and ticket it. 4. Review on a documented cadence and capture the review in the risk register or compliance tracker. ### Operational checklist - **Access.** Document the trigger, the owner and the cadence. - **Security.** Document the trigger, the owner and the cadence. - **Enable.** Document the trigger, the owner and the cadence. - **Data.** Document the trigger, the owner and the cadence. - **Review.** Document the trigger, the owner and the cadence. - **Scope:** management, domains, authentication, system, service, source, protection, identity. ## Evidence to collect - **Identity Scan.** IAM / IdP exports — Entra ID, Okta, IAM Identity Center, Workspace directory — showing accounts, roles, MFA state and last sign-in. Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Focus: Secure Name/Address Resolution Service (Authoritative Source). ## How it maps to other frameworks Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit. - [**NIST SP 800-171 Rev. 3 3.15.2** — System Security Plan](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-15-2-system-security-plan) - [**CIS Controls v8 5.6** — Centralize Account Management](https://support.icompaas.com/compliance/cis-controls-v8/5-6-centralize-account-management) ## Related controls in NIST SP 800-53 Rev. 5 - [**Control SC-20(2)** — Data Origin And Integrity](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-20-2-data-origin-and-integrity) - [**Control SC-21** — Secure Name/Address Resolution Service (Recursive Or Caching Resolver)](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-21-secure-name-address-resolution-service-recursive-or-caching-resolver) - [**Control SC-23** — Session Authenticity](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-23-session-authenticity) - [**Control SC-45** — System Time Synchronization](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-45-system-time-synchronization) - [**Control SC-32(1)** — Separate Physical Domains For Privileged Functions](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-32-1-separate-physical-domains-for-privileged-functions) - [**Control SC-2** — Separation Of System And User Functionality](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-2-separation-of-system-and-user-functionality) ## References - [NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5](https://csrc.nist.gov/Projects/risk-management/sp800-53-controls) - Catalogue identifier: `Control SC-20` Topics: identity accessidentity managementaccess reviewprivileged access ## Related compliance guidance - [NIST SP 800-53 Rev. 5: a practical implementation guide for cloud teams](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5): Start with the full NIST SP 800-53 implementation guide — scope, roadmap, evidence and how the assessment runs. - [NIST SP 800-171 and CMMC: a practical guide to protecting CUI in the cloud](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3): If your obligation is protecting CUI in your own systems for a federal or defence contract, this derived subset — not the full catalogue — is the requirement. - [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Most commercial SaaS already hold a SOC 2 Type 2, and FedRAMP 20x Class A is designed for providers that have one.